Poultry producers understand that good quality water containing acceptable levels of mineral contaminants supports poultry flock health and livability. Productivity improves while the use of therapeutic treatments is reduced, equipment problems are prevented, and the sustainability of commercial poultry production is improved. High levels of iron in drinking water do not impose any direct health concerns for poultry, but systems with high iron may exhibit increased biofilm formation in water lines and also lead to water equipment malfunction. It is important to test water samples for iron levels regularly and treat the water accordingly.
Iron occurs naturally in water, usually at less than 1 mg/litre, but up to 100 mg/liter in groundwater. Any iron levels less than 0.2 mg/litre fall into the best practice level; between 0.2 and 0.3 mg/litre are acceptable, and any values above 0.3 mg/litre are above the acceptable level. Birds can tolerate iron. A study conducted by Fairchild et. al. at the University of Georgia suggested that broiler tolerance for iron in drinking water was up to 600 ppm. That being said, high iron concentration in water promotes the growth of pathogens and other farm challenges. Iron particles feed bacteria (like Pseudomonas, Salmonella, and E-coli), so if your water has excessive levels of iron, the water is prone to contamination. In addition, high levels of iron cause water system scaling, which may result in the malfunctioning of watering equipment and lead to water deprivation. Iron oxide precipitant can get into the nipple drinker mechanism and result in leaky nipples. This results in poor litter conditions, increasing ammonia levels and compromising birds’ performance.
Water and equipment observational tests
On-farm observational tests on your drinking water can help identify a problem with levels of high iron. The fist step is to collect water samples from the water source, water after treatment, and the end of the water line. Each water sample should be taken in two glasses. You will need to run some tests on the fresh water sample and some tests on a water sample after sitting for a minimum of 4 hours in a glass.
Below are four examples of problematic iron levels after testing. If you come up with the following results, you should check the water iron level by sending a water sample to a lab for iron analysis or using an on-farm water iron meter tool. A detailed explanation of the standard operating procedure of the water iron meter can be found in our previous tool of the month article.
If you have high iron levels in your water you might observe the following:
- The appearance of your fresh drinking water sample is gray, brown, or black
- If you let the water sit for a minimum of 4 hours in a glass, the color of the water changes to yellow, brown, or reddish-brown.
- The odor or taste of the fresh water sample is metallic or bitter
- Any equipment in contact with water, such as water filters, water lines, fogging nozzles, and evaporative cooling systems, should also be monitored for any signs that might suggest a problem. Test the water for iron if it leaves behind any brown or reddish-brown residue (stains, film, or scale) on the surfaces.
Treatment of high iron in drinking water
Iron removal is probably the most practical approach to effectively dealing with high iron content in water. The following methods can be taken to manage the issue.
- Coagulation is a method to remove fine particles, iron, arsenic, and manganese. The coagulation chemicals, such as aluminum sulfate, neutralize the charge on the particles and cause particles to coalesce into floc (a loosely clumped mass of fine particles) that can be removed by filtration or settling. The removal of particles prior to chlorination makes disinfection much more effective.
- Some filters, such as manganese greensand filters, slow sand filters, nano-filters, or reverse-osmosis membranes, may be effective in reducing iron in drinking water.
- Oxidation with chlorine, chlorine dioxide, or ozone and then filtration removal with proper-sized mechanical filtration.
- Biologically activated carbon with pre-oxidation: Biological Activated Carbon (BAC) is a water purification process that combines physical adsorption onto granular activated carbon and pollutants/organics biodegradation through biofilms. More information about the BAC system is available at Wageningen University and Research website.
- Shock chlorination of well water is recommended to eliminate bacterial contamination and to reduce iron-fixing bacteria and hydrogen sulfide-producing bacteria in the water source. Shock chlorination can be done using household liquid bleach or chlorine tablets / coated calcium hypochlorite tablets. The goal is to achieve 100-200 part-per-million (ppm) chlorine in the system for optimal shock chlorination. To reach these levels of chlorine, use approximately 3 pints (about 1.5 liters) of liquid bleach per 100 gallons (about 378 liters) of water. Notice that these levels of chlorine are not safe for human and animal consumption, so this method should be done only between flocks when there are no birds in the barn. Remove any activated carbon filters that might be in the system to prevent filter damage.
In conclusion, iron in water is an important factor to consider in poultry production. Ramifications of high levels of iron in water can compromise bird health and increase the water system maintenance cost. Regularly testing water samples for iron levels and taking steps to manage high levels can help ensure the health and productivity of your flock.
References
Fairchild, B. D., A. B. Batal, C. W. Ritz, and P. F. Vendrell. 2006. Effect of drinking water iron concentration on broiler performance. J. Appl. Poult. Res. 15:511–517. (Link)
Harry Bruning. 2019. Potential of an innovative ultrapure water production plant with biological activated carbon filters. Wageningen University and Research. (Link)
The Extension Poultry Housing program of Auburn University. 2000. Key Water Factors for Broiler Production. Auburn University Poultry Ventilation and Housing Newsletter No. 7. Page 65-69. (Link)
Watkins, S. 2008. Water: Identifying and Correcting Challenges. AVIAN Advice. Avian Advice. University of Arkansas Cooperative Extension Service, Fayetteville, AR. Vol. 10, No. 3. Pages 10 – 15. (Link)
Watkins, S. 2015. Optimizing Water Quality for Organic Bird Production. Midwest Poultry. (Link)
